It is known that hypothalamic hormone or pituitary hormone takes part in a control system of secretion of peripheral hormones. In general, the secretion of anterior pituitary hormone is regulated by a secretion stimulating hormone or a secretion suppressing hormone secreted from an upper center, hypothalamus, a peripheral hormone secreted from the target organs them.
Gonadotropin releasing hormone (hereinafter, abbreviated as GnRH; also, GnRH is called as luteinizing hormone releasing hormone; LHRH) is known as a hormone which controls the secretion of sex hormones at the highest position, and regulates the secretion of luteinizing hormone (hereinafter, abbreviated as LH), follicle stimulating hormone (hereinafter, abbreviated as FSH), and sex hormones in the gonads through the intermediary of the receptor (hereinafter, abbreviated as GnRH receptor) which is considered to be present in anterior pituitary (Horumon to Rinsyo (Hormones and Clinical), 46, 46-57 (1998)). A specific and selective antagonist against the GnRH receptor is expected to be a drug for preventing and treating sex hormone-dependent diseases since it regulates the action of GnRH and controls the secretion of lower LH, FSH and sex hormones (Horumon to Rinsyo (Hormones and Clinical) (1998), ibid.).
As compounds having a GnRH receptor antagonistic property, peptide compounds such as linear peptides, cyclic hexapeptide derivatives and bicyclic peptide derivatives which are derivatives of GnRH have been known. Also, as non-peptide compounds having the property, the following aminobenzimidazole derivatives (Japanese Patent Laid-Open No. 95767/2000), thienopyrimidine derivatives (WO 95/28405), or the like has been reported. (refer to the above publications for the symbols in the formulae)
On the other hand, the known propane-1,3-dione derivatives having a benzimidazole, benzothiazole, or benzoxazole skeleton described in the following Table 1 have been reported as reagents for use as photosensitizer or the like (EP-A-135348, EP-A-631177, EP-A-368327, EP-A-332044, WO 94/01415, U.S. Pat. No. 4,062,686, U.S. Pat. No. 4,119,466, Collect. Czech. Chem. Commun. (1971), 36(1), 150-63, Zh. Nauch. Prikl. Fotogr. Kinematogr. (1971), 16(4), 282-8, Collect. Czech. Chem. Commun. (1978), 43(3), 739-45, Collect. Czech. Chem. Commun. (1979), 44(5), 1540-51, and Collect. Czech. Chem. Commun. (1973), 38(12), 3616-22), but pharmaceutical actions, particularly a GnRH receptor antagonistic action have not been disclosed.